Born On The Bayou Tremolo. This is an optical tremolo pedal I made using Madbean's Double Flush project board.

The controls are:

BALANCE, which controls the mix between effect and guitar signals.

INTENSITY, which controls how hard the LED is driven. Turning up the control increases the intensity of tremolo.

PULSE, which controls the rate of the LFO. There's a wide range of slow to fast, with the maximum range stopping just before the tremolo becomes un-useable.

VOLUME, the overall output. Note that changing the Balance control may require some changes in the Volume control to preserve the overall output. There is enough gain in the circuit to maintain or exceed the bypass signal.